fn DecodeContextMapInner<AllocU8: Allocator<u8>, AllocU32: Allocator<u32>, AllocHC: Allocator<HuffmanCode>>(
    context_map_size: u32,
    num_htrees: &mut u32,
    context_map_arg: &mut AllocU8::AllocatedMemory,
    s: &mut BrotliState<AllocU8, AllocU32, AllocHC>,
    input: &[u8]
) -> BrotliDecoderErrorCode